A vehicle hybrid drive device is known (a) that includes a first rotating machine coupled to an engine, a connection/disconnection device capable of connecting/disconnecting the engine and the first rotating machine to/from wheels, and a second rotating machine disposed in a manner enabling transmission of drive power to the wheels and that enables a vehicle to run in two running modes of (b) an EV (electric vehicle) running mode enabling the vehicle to run with the second rotating machine used as a drive power source while the connection/disconnection device is disconnected and (c) a parallel HEV (hybrid electric vehicle) running mode enabling the vehicle to run with the engine and at least one of the first and second rotating machines as the drive power sources while the connection/disconnection device is connected. One example is a device described in Patent Document 1 and an engine running region of FIG. 2 of this publication corresponds to the parallel HEV running mode. A vehicle can also run in a series HEV running mode in which the connection/disconnection device is disconnected to enable the vehicle to run with the second rotating machine as the drive power source while the first rotating machine is rotationally driven to generate electricity by the engine disconnected from the wheels and, for example, the series HEV running mode is implemented in an intermediate region between an EV region for running in the EV running mode and a parallel HEV region for running in the parallel HEV running mode.